The Three Commercial Lease Structures

Commercial leases fall into three broad categories, and understanding which one you're dealing with is the foundation of everything else in property management.

Gross lease (full-service lease): The tenant pays a flat base rent. The landlord covers all operating expenses — property taxes, insurance, maintenance, utilities. The tenant's monthly obligation is fixed and predictable. The landlord absorbs all cost variability.

Triple net lease (NNN): The tenant pays base rent plus their proportionate share of three "nets": property taxes, building insurance, and maintenance/operating expenses. The landlord passes most operating cost risk to tenants. The tenant's monthly cost varies as actual expenses change.

Modified gross lease (MG or net lease): A hybrid. The tenant pays base rent plus some expenses but not others. The specific split is negotiated lease by lease — you might see a tenant responsible for utilities and their share of taxes, but the landlord covering insurance and structural maintenance.

In practice, the modified gross lease is a catch-all for every arrangement that doesn't fit neatly into the other two categories.

What a Gross Lease Means for Property Managers

Gross leases are simple to administer. You collect rent. You pay operating expenses. At the end of the year, you don't owe tenants any reconciliation or accounting of how much you spent — the tenant's obligation is fixed regardless.

This simplicity makes gross leases common in:

• Office buildings with multiple small tenants
• Retail strip centers with short-term or month-to-month tenants
• Industrial spaces where tenants have limited capital and prefer cost predictability

The downside for landlords is real: if operating costs spike — a brutal winter drives heating bills up, the parking lot needs full replacement, insurance premiums jump — the landlord absorbs 100% of the increase. Gross lease tenants are insulated from cost volatility by design.

From a software perspective, gross lease management is straightforward. Your accounting system handles it. You collect rent, pay bills, and track profit. Most general-purpose property management software is built for this model.

What a Triple Net Lease Means for Property Managers

NNN leases shift the cost risk — and the administrative burden. When the tenant is responsible for their share of operating expenses, you have to:

• Track three categories of expenses (taxes, insurance, CAM/maintenance) separately and allocate them by tenant
• Bill estimated CAM charges monthly based on projected expenses
• Reconcile annually to true up the difference between estimates and actuals
• Apply lease-specific terms — each tenant's lease may contain different caps, exclusions, base years, and pro-rata methodologies
• Monitor rent escalations — NNN leases often include fixed annual rent bumps or CPI-based escalations that must be tracked and applied on the correct date
• Track option deadlines — purchase options, renewal options, and termination rights have specific notice windows that, if missed, can have major financial consequences

The operational complexity of a single NNN property can exceed that of a multi-building gross lease portfolio. This is why NNN-heavy operators often struggle with general-purpose property software — the tools weren't built for this level of lease-driven accounting.

The Modified Gross Lease: A Middle Ground

Modified gross leases require you to know — in precise detail — what each tenant is and isn't responsible for. There is no industry standard for what "modified gross" means. Every lease is different.

Some MG leases look almost identical to gross leases, with only utilities passed through. Others look nearly like NNN leases, with tenants responsible for everything except structural repairs and roof. The only way to administer them correctly is to have a complete, current lease abstract for every tenant.

Why NNN Leases Dominate Retail Commercial Real Estate

The shift toward NNN structures in retail has been consistent for decades, driven by a few factors:

• Long lease terms — NNN leases at national retail locations often run 10–25 years. Over that horizon, fixed gross rent would require landlords to forecast operating costs accurately decades out, which is impossible. NNN structures pass the uncertainty to tenants.
• Institutional ownership — REIT and institutional ownership of retail commercial property accelerated NNN adoption because institutional investors prefer predictable NOI and want to pass operating variability to tenants.
• Tenant creditworthiness — National tenants (fast food chains, dollar stores, pharmacies, big-box retailers) are sophisticated enough to underwrite NNN lease terms and accept the cost structure.
• CAP rate clarity — NNN properties are easier to value because NOI is more stable and predictable.

Independent commercial property managers typically encounter NNN structures primarily in single-tenant retail, neighborhood retail centers, and mixed-use strips with credit tenants.

What This Means for Your Management Software Choice

Most general-purpose property management software — AppFolio, DoorLoop, Buildium, and others — was designed primarily for residential and gross lease commercial properties. They handle rent collection, maintenance requests, and basic accounting. They don't handle:

• CAM reconciliation with cap and exclusion logic
• Lease-specific pro-rata share calculations
• Annual reconciliation statement generation
• Rent escalation tracking with CPI or fixed bump schedules
• NNN option deadline monitoring

> If your portfolio is predominantly NNN retail or commercial properties, you need software designed for NNN operations — not residential software that happens to also do commercial.

This is the gap PigJet was built to fill. Rather than forcing NNN operators to adapt residential-first tools, PigJet starts from the NNN lease structure and works outward. Learn more about NNN lease management in PigJet →